It is observed that `H_(2)` and He gases always show positive deviation from ideal behaviour i.e ., `Zgtl`. This is because
A. the value of a is very large due to high attractive forces
B. the weak intermolecular forces of attraction due to which a is very small and `a/V^(2)` is negligible
C. the value of b is very large due to large size of the molecules
D. both a and b are very small and negligible .
